Lumber



W. C. GOSS Oct. 8, 1940.

LUMBER Filed Nov. 16, 1937 INVENTOR ATTORNEY Patented Oct. 8, 1940 UNITED STATES @PATENT OFFICE a in 4 Claims.

This invention relates to lumber and deals particularly with the improvement of lumber which may be more or less defective by reason of its containing knots, pitch pockets, stains, scars and the like. More specifically stated, this invention relates to the repairing and improvement of lumber, that is defective by reason of the above stated causes, by the removal of the defective portion and the fitting of a patch piece within the pocket formed by the removal of the defect.

The present invention is in the nature of an improvement in the shaping of the patch piece and recess made to receive it, as disclosed in U. S. Patent No. 1,976,722 issued on October 16, 1934 to Oliver P. M. Goss and Worth C. Goss.

It has been found by actual manufacture in accordance with the Gross et al. patent, above mentioned that there is a possibility, when pressing the patches into place, to cause splitting of the board by reason of the unstopped wedging action between interfitted parts at the ends of patch and pocket. Furthermore, since the opposite side Walls of the patch and pocket are parallel, and are designed to make a tight fitting joint, there is the objectionable feature of the glue, which is applied to the patch pieces prior to their being inserted, being scraped ofi' the side surfaces of the patch when it is pressed in.

Also, it has been found impracticable, and practically impossible to make all pockets and all patch pieces with exactly the same dimensions due to the fact that the cutters whereby these parts are formed must of necessity be frequently sharpenedand sharpening naturally shortens the knives. As a consequence, some patches may be shorter or longer than others and therefore may drop farther into or not so far into the pockets.

More specifically stated, the objects of this invention reside in the provision of positive stops for limiting the extent to which the patch pieces may be pressed into the pockets, and to thereby overcome the tendency to split the piece, also in the provision of patches and pockets having a slight taper to the side walls that will permit the patches to be dropped into place, but which taper is not of such degree that the diiierence in extent to which patch pieces may enter the pockets before seating will have any material bearing on the tightness of the glue joints along the sides of the patches.

Other objects of the invention reside in the details of construction and relationship of parts whereby manufacturing problems are reduced to a minimum, and a more satisfactory product insured.

In accomplishing these objects I have provided the improved details of construction, the preferred forms of which are illustrated inthe accompanying drawing, wherein- Fig. 1 is a perspective view of a piece of lumber to which a patch piece has been applied in accordance with this invention, and showing also an open pocket in the piece and a patch ready for insertion thereinto.

Fig. 2 is a view of a pieceof board, showing a pocket prepared therein in tails of this invention. Fig. 3 is a longitudinal section through a patched piece of lumber, showing the seating surface at the end of a patch.

Fig. 4 is a cross section on the piece on the line accordance with deaccordance with the present invention. 3 designates a pocket that has been prepared at another place in the board for reception of a patch 20. which is shown directly above the pocket; it being understood that all patch pieces and all pockets are alike in size and shape except for 1;

slight variation hereinafter noted, and any patch piece may be applied in any pocket.

In the manufacture of this lumber, the boards l are delivered in blanked form. Usually they are delivered from the dry kiln, through theblanking machine which takes off the rough surface, then taken to pocket routing machines whereby the defects such as knots, pitch pockets, scars, etc., are removed from the piece; the operation leaving at the location of the' defect, an".

elongated, substantially rectangular pocket 3 through the board for the reception of a patch 2. The pockets are formed lengthwise of the board and grain of wood and, as a rule, are approximately five times as long as they are wide. Inthe manufacturing operation,'the router forms the pockets entirely through the board and' in the present instance provides the ends of each pocket with alternating, long and narrow V-shape ridges 5 and grooves 6;

by reason of the character of the knives used in the routing machines, are symmetrically tapered in the direction of thickness of the board, and

the side surfaces 1 of the pocket are just slightly These grooves, l

beveled so as to taper the opening and produce a sliding fit when the patch piece, which is similarly tapered, is dropped thereinto.. Also the side surfaces are just slightly outwardly bowed from end to end as will be noted by reference to Fig. 2.

In the illustration, the patch is shown as having four teeth at each end. It is intended however, that the number of teeth shall be as many as practical to make. Preferably the included angle would be approximately 11. 1

The patch pieces 2 are shaped to fit the pockets and each is formed at its opposite ends with V-shaped grooves 11 and ridges 18 to interfit with the ridges and grooves at the ends of the pockets. Also each patch has its side surfaces 20 beveled to give the patch a slight taper corresponding to the taper of the pocket.

Prior to applying a patch in a pocket, glue is applied to the opposite end portions of the patch and along its side surfaces, and it is a feature of this application that, by reason of the taper, the patch may be dropped into place and without scraping off any of the'glue.

As a feature of this invention, the pockets are designed to provide a positive stop for seating of the patches therein. It will be understood by referring to Figs. 4 and 5, that the V-shaped grooves at the ends of the pockets, are tapered in the direction of thickness from top to bottom of the lumber piece as previously stated, and that when the V-shaped ridges at the opposite ends of the patch are fitted therein and the patch pressed into place, there will be a wedging fit between these parts. However, since it is not desirable that this wedging action be unrestricted, I have formed a square cut seat 22 at a positivestop for the patch that eliminates tend-' ency .toward splitting and positively limits the extent to which the patch enters the recess or pocket.

It is especially to be pointed out that the abutting seats thus provided bring the opposed parts of the pocket and patch into end grain abutment and the wedging forces are applied in a lengthwise direction of the board and not transversely. Thus, the patch may be seated in I description, it is apparent that a patch piece may bedropped into place, and pressure applied there i against to firmly seat it in the pocket. Furthermore, it is apparent that by reason of the rather abrupt curvature of the seats at the ends of the pocket and the relatively slight angle of taper of the side walls, a patch piece may enter a pocket to a more or less extent without to any appreciable extent effecting the joint between the side walls of the patch and of the pocket. In other words, the variation in the lengths of pockets and variation in the lengths of patches,

thatis incident to sharpening and adjusting of the-router and forming knives, is compensated for by the provision that the patch may drop to a more or less extent into the pocket and the movement of the patch whether it extends above the surface of the board or dropped below the surface, is of no particular consequence for the reason that the very slight angle of taper maintains the side joints sufficiently close that they will always be filled with the glue applied to the side surfaces of the patch. Furthermore, the lateral yield in the wood along the side joints will compensate for any unusual tightness that might result from a patch dropping farther than intendedinto a pocket.

While I have illustrated the patch and pocket as having grooves and ridges at their ends for intermeshing, I do not wish to be confined to that detail, for it is possible to make lumber within the scope of this invention where these parts are not toothed; it being the intention that this application shall be based upon the relationship of the end seats which afford a positive stop to eliminate splitting, and a tapered patch which may enter to a more or less extent without to any material extent affecting the fit of the glued side joints.

United States Patent No. 1,878,081, to A. R. Welch, discloses use of veneer patch pieces, the opposite sides of which are curved and the patch tapered. While this is not particularly pertinent, it is mentioned in order to cite a differentiation particularly in that in the patent there is no material distinction between the angle of taper at the sides and ends of the patch, and that renders it an impractical proposition for patching lumber of the present kind. Such a patch, as seen in the Welch patent provides stopping surfaces entirely about the patch and that is what the present invention avoids, since it is extremely desirable that there be no lateral wed'ging and that all strain shall be directed endwise of the grain of the interfitted parts.

Lumber repaired in accordance with this in.- vention is rendered of higher classification by reason of the fact that its strength is brought up to a maximum, its appearance enhanced and its length maintained.

Having thus described my invention, what I claim as new therein and desire to secure by Letters Patent is- 1. A piece of commercial lumber formed with a defect removing pocket of rectangular form extending therethrough and a wood patch piece having a form corresponding to that of the pocket fitted in the pocket and secured therein by glued joints; said pocket having its opposite end surfaces formed crosswise of the grain of the piece and inwardly sloped to a degree sufficient that they will serve as abutment surfaces for seating the patch piece when it is pressed into the pocket and having its opposite side surfaces beveled to taper the pocket in its direction through the lumber; said patch being formed lengthwise of the grain of the wood and having its opposite ends sloped corresponding to the slope of the ends of the pocket and having its opposite sides beveled in accordance with' the bevel of the side walls of the pocket whereby the patch may be dropped freely into the pocket to form a close joint when the patch is seated but not to act as a positive stop at any position of insertion.

2. A piece of commercial lumber having a defect removing pocket of substantially rectangular form extending therethrough extending in the direction of the grain of the board, and a patch piece having a form corresponding to that of the pocket with grain parallel to that of the board, fitted in said pocket and secured therein by glued joints; said pocket having its opposite end surfaces curved about an axis of rotation at one side of the lumber piece to form abutment surfaces for seating the ends of the patch piece when it is pressed into place in the pocket, and having its opposite side surfaces slightly beveled to give a taper to the pocket in its direction through the lumber; said patch piece having its opposite ends curved to fit the abutment surfaces at the ends of the pocket and having its side Walls beveled in accordance with the bevel of the side walls of the pocket, whereby to permit the patch being dropped freely into the pocket and to form a close joint when the patch is seated, but not acting as a limiting stop at any position of insertion of the patch.

3. A piece of commercial lumber as recited in claim 2, wherein the opposite end surfaces of the pocket and patch are formed with interfitting V-shaped grooves and ridges formed with square cut abutment surfaces at their ends.

4. A piece of commercial lumber formed with an elongated, rectangular pocket extending therethrough and in the direction of the grain, and a patch piece fitted and glued within the pocket; said pocket having its opposite end surfaces curved about an axis of rotation parallel with and spaced from the top surface of the lumber piece and formed with a series of alternating V-shaped grooves and ridges with squarecut abutment surfaces at their ends and having its opposite side surfaces slightly, and uniformly curved in an outward direction from end to end of the pocket and slightly beveled to pro- Vide easy entrance of the patch in a slidingfit without positive seating; said patch piece having its opposite end surfaces curved in accordance with the end surfaces of the pocket formed with a series of V-shaped grooves and ridges with square-cut abutment surfaces at their ends to interfit with those of the pocket and having its side wallscurved and beveled in accordance with the curve and bevel of the side walls of the pocket.

WORTH C. GOSS. 

